[deliverable/linux.git] / arch / x86 / include / asm / atomic.h

#ifndef _ASM_X86_ATOMIC_H
#define _ASM_X86_ATOMIC_H

#include <linux/compiler.h>
#include <linux/types.h>
#include <asm/processor.h>
#include <asm/alternative.h>
#include <asm/cmpxchg.h>

/*
 * Atomic operations that C can't guarantee us.  Useful for
 * resource counting etc..
 */

#define ATOMIC_INIT(i)	{ (i) }

/**
 * atomic_read - read atomic variable
 * @v: pointer of type atomic_t
 *
 * Atomically reads the value of @v.
 */
static inline int atomic_read(const atomic_t *v)
{
	return (*(volatile int *)&(v)->counter);
}

/**
 * atomic_set - set atomic variable
 * @v: pointer of type atomic_t
 * @i: required value
 *
 * Atomically sets the value of @v to @i.
 */
static inline void atomic_set(atomic_t *v, int i)
{
	v->counter = i;
}

/**
 * atomic_add - add integer to atomic variable
 * @i: integer value to add
 * @v: pointer of type atomic_t
 *
 * Atomically adds @i to @v.
 */
static inline void atomic_add(int i, atomic_t *v)
{
	asm volatile(LOCK_PREFIX "addl %1,%0"
		     : "+m" (v->counter)
		     : "ir" (i));
}

/**
 * atomic_sub - subtract integer from atomic variable
 * @i: integer value to subtract
 * @v: pointer of type atomic_t
 *
 * Atomically subtracts @i from @v.
 */
static inline void atomic_sub(int i, atomic_t *v)
{
	asm volatile(LOCK_PREFIX "subl %1,%0"
		     : "+m" (v->counter)
		     : "ir" (i));
}

/**
 * atomic_sub_and_test - subtract value from variable and test result
 * @i: integer value to subtract
 * @v: pointer of type atomic_t
 *
 * Atomically subtracts @i from @v and returns
 * true if the result is zero, or false for all
 * other cases.
 */
static inline int atomic_sub_and_test(int i, atomic_t *v)
{
	unsigned char c;

	asm volatile(LOCK_PREFIX "subl %2,%0; sete %1"
		     : "+m" (v->counter), "=qm" (c)
		     : "ir" (i) : "memory");
	return c;
}

/**
 * atomic_inc - increment atomic variable
 * @v: pointer of type atomic_t
 *
 * Atomically increments @v by 1.
 */
static inline void atomic_inc(atomic_t *v)
{
	asm volatile(LOCK_PREFIX "incl %0"
		     : "+m" (v->counter));
}

/**
 * atomic_dec - decrement atomic variable
 * @v: pointer of type atomic_t
 *
 * Atomically decrements @v by 1.
 */
static inline void atomic_dec(atomic_t *v)
{
	asm volatile(LOCK_PREFIX "decl %0"
		     : "+m" (v->counter));
}

/**
 * atomic_dec_and_test - decrement and test
 * @v: pointer of type atomic_t
 *
 * Atomically decrements @v by 1 and
 * returns true if the result is 0, or false for all other
 * cases.
 */
static inline int atomic_dec_and_test(atomic_t *v)
{
	unsigned char c;

	asm volatile(LOCK_PREFIX "decl %0; sete %1"
		     : "+m" (v->counter), "=qm" (c)
		     : : "memory");
	return c != 0;
}

/**
 * atomic_inc_and_test - increment and test
 * @v: pointer of type atomic_t
 *
 * Atomically increments @v by 1
 * and returns true if the result is zero, or false for all
 * other cases.
 */
static inline int atomic_inc_and_test(atomic_t *v)
{
	unsigned char c;

	asm volatile(LOCK_PREFIX "incl %0; sete %1"
		     : "+m" (v->counter), "=qm" (c)
		     : : "memory");
	return c != 0;
}

/**
 * atomic_add_negative - add and test if negative
 * @i: integer value to add
 * @v: pointer of type atomic_t
 *
 * Atomically adds @i to @v and returns true
 * if the result is negative, or false when
 * result is greater than or equal to zero.
 */
static inline int atomic_add_negative(int i, atomic_t *v)
{
	unsigned char c;

	asm volatile(LOCK_PREFIX "addl %2,%0; sets %1"
		     : "+m" (v->counter), "=qm" (c)
		     : "ir" (i) : "memory");
	return c;
}

/**
 * atomic_add_return - add integer and return
 * @i: integer value to add
 * @v: pointer of type atomic_t
 *
 * Atomically adds @i to @v and returns @i + @v
 */
static inline int atomic_add_return(int i, atomic_t *v)
{
	int __i;
#ifdef CONFIG_M386
	unsigned long flags;
	if (unlikely(boot_cpu_data.x86 <= 3))
		goto no_xadd;
#endif
	/* Modern 486+ processor */
	__i = i;
	asm volatile(LOCK_PREFIX "xaddl %0, %1"
		     : "+r" (i), "+m" (v->counter)
		     : : "memory");
	return i + __i;

#ifdef CONFIG_M386
no_xadd: /* Legacy 386 processor */
	raw_local_irq_save(flags);
	__i = atomic_read(v);
	atomic_set(v, i + __i);
	raw_local_irq_restore(flags);
	return i + __i;
#endif
}

/**
 * atomic_sub_return - subtract integer and return
 * @v: pointer of type atomic_t
 * @i: integer value to subtract
 *
 * Atomically subtracts @i from @v and returns @v - @i
 */
static inline int atomic_sub_return(int i, atomic_t *v)
{
	return atomic_add_return(-i, v);
}

#define atomic_inc_return(v)  (atomic_add_return(1, v))
#define atomic_dec_return(v)  (atomic_sub_return(1, v))

static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
{
	return cmpxchg(&v->counter, old, new);
}

static inline int atomic_xchg(atomic_t *v, int new)
{
	return xchg(&v->counter, new);
}

/**
 * atomic_add_unless - add unless the number is already a given value
 * @v: pointer of type atomic_t
 * @a: the amount to add to v...
 * @u: ...unless v is equal to u.
 *
 * Atomically adds @a to @v, so long as @v was not already @u.
 * Returns non-zero if @v was not @u, and zero otherwise.
 */
static inline int atomic_add_unless(atomic_t *v, int a, int u)
{
	int c, old;
	c = atomic_read(v);
	for (;;) {
		if (unlikely(c == (u)))
			break;
		old = atomic_cmpxchg((v), c, c + (a));
		if (likely(old == c))
			break;
		c = old;
	}
	return c != (u);
}

#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)

/*
 * atomic_dec_if_positive - decrement by 1 if old value positive
 * @v: pointer of type atomic_t
 *
 * The function returns the old value of *v minus 1, even if
 * the atomic variable, v, was not decremented.
 */
static inline int atomic_dec_if_positive(atomic_t *v)
{
	int c, old, dec;
	c = atomic_read(v);
	for (;;) {
		dec = c - 1;
		if (unlikely(dec < 0))
			break;
		old = atomic_cmpxchg((v), c, dec);
		if (likely(old == c))
			break;
		c = old;
	}
	return dec;
}

/**
 * atomic_inc_short - increment of a short integer
 * @v: pointer to type int
 *
 * Atomically adds 1 to @v
 * Returns the new value of @u
 */
static inline short int atomic_inc_short(short int *v)
{
	asm(LOCK_PREFIX "addw $1, %0" : "+m" (*v));
	return *v;
}

#ifdef CONFIG_X86_64
/**
 * atomic_or_long - OR of two long integers
 * @v1: pointer to type unsigned long
 * @v2: pointer to type unsigned long
 *
 * Atomically ORs @v1 and @v2
 * Returns the result of the OR
 */
static inline void atomic_or_long(unsigned long *v1, unsigned long v2)
{
	asm(LOCK_PREFIX "orq %1, %0" : "+m" (*v1) : "r" (v2));
}
#endif

/* These are x86-specific, used by some header files */
#define atomic_clear_mask(mask, addr)				\
	asm volatile(LOCK_PREFIX "andl %0,%1"			\
		     : : "r" (~(mask)), "m" (*(addr)) : "memory")

#define atomic_set_mask(mask, addr)				\
	asm volatile(LOCK_PREFIX "orl %0,%1"			\
		     : : "r" ((unsigned)(mask)), "m" (*(addr))	\
		     : "memory")

/* Atomic operations are already serializing on x86 */
#define smp_mb__before_atomic_dec()	barrier()
#define smp_mb__after_atomic_dec()	barrier()
#define smp_mb__before_atomic_inc()	barrier()
#define smp_mb__after_atomic_inc()	barrier()

#ifdef CONFIG_X86_32
# include "atomic64_32.h"
#else
# include "atomic64_64.h"
#endif

#include <asm-generic/atomic-long.h>
#endif /* _ASM_X86_ATOMIC_H */
Commit	Line	Data
5abbbbf0 BG	1	#ifndef _ASM_X86_ATOMIC_H
	2	#define _ASM_X86_ATOMIC_H
	3
	4	#include <linux/compiler.h>
	5	#include <linux/types.h>
	6	#include <asm/processor.h>
	7	#include <asm/alternative.h>
	8	#include <asm/cmpxchg.h>
	9
	10	/*
	11	* Atomic operations that C can't guarantee us. Useful for
	12	* resource counting etc..
	13	*/
	14
	15	#define ATOMIC_INIT(i) { (i) }
	16
	17	/**
	18	* atomic_read - read atomic variable
	19	* @v: pointer of type atomic_t
	20	*
	21	* Atomically reads the value of @v.
	22	*/
	23	static inline int atomic_read(const atomic_t *v)
	24	{
f3d46f9d	25	return ((volatile int )&(v)->counter);
5abbbbf0 BG	26	}
	27
	28	/**
	29	* atomic_set - set atomic variable
	30	* @v: pointer of type atomic_t
	31	* @i: required value
	32	*
	33	* Atomically sets the value of @v to @i.
	34	*/
	35	static inline void atomic_set(atomic_t *v, int i)
	36	{
	37	v->counter = i;
	38	}
	39
	40	/**
	41	* atomic_add - add integer to atomic variable
	42	* @i: integer value to add
	43	* @v: pointer of type atomic_t
	44	*
	45	* Atomically adds @i to @v.
	46	*/
	47	static inline void atomic_add(int i, atomic_t *v)
	48	{
	49	asm volatile(LOCK_PREFIX "addl %1,%0"
	50	: "+m" (v->counter)
	51	: "ir" (i));
	52	}
	53
	54	/**
	55	* atomic_sub - subtract integer from atomic variable
	56	* @i: integer value to subtract
	57	* @v: pointer of type atomic_t
	58	*
	59	* Atomically subtracts @i from @v.
	60	*/
	61	static inline void atomic_sub(int i, atomic_t *v)
	62	{
	63	asm volatile(LOCK_PREFIX "subl %1,%0"
	64	: "+m" (v->counter)
	65	: "ir" (i));
	66	}
	67
	68	/**
	69	* atomic_sub_and_test - subtract value from variable and test result
	70	* @i: integer value to subtract
	71	* @v: pointer of type atomic_t
	72	*
	73	* Atomically subtracts @i from @v and returns
	74	* true if the result is zero, or false for all
	75	* other cases.
	76	*/
	77	static inline int atomic_sub_and_test(int i, atomic_t *v)
	78	{
	79	unsigned char c;
	80
	81	asm volatile(LOCK_PREFIX "subl %2,%0; sete %1"
	82	: "+m" (v->counter), "=qm" (c)
	83	: "ir" (i) : "memory");
	84	return c;
	85	}
	86
	87	/**
	88	* atomic_inc - increment atomic variable
	89	* @v: pointer of type atomic_t
90	*
91	* Atomically increments @v by 1.
92	*/
93	static inline void atomic_inc(atomic_t *v)
94	{
95	asm volatile(LOCK_PREFIX "incl %0"
96	: "+m" (v->counter));
97	}
98
99	/**
100	* atomic_dec - decrement atomic variable
101	* @v: pointer of type atomic_t
102	*
103	* Atomically decrements @v by 1.
104	*/
105	static inline void atomic_dec(atomic_t *v)
106	{
107	asm volatile(LOCK_PREFIX "decl %0"
108	: "+m" (v->counter));
109	}
110
111	/**
112	* atomic_dec_and_test - decrement and test
113	* @v: pointer of type atomic_t
114	*
115	* Atomically decrements @v by 1 and
116	* returns true if the result is 0, or false for all other
117	* cases.
118	*/
119	static inline int atomic_dec_and_test(atomic_t *v)
120	{
121	unsigned char c;
122
123	asm volatile(LOCK_PREFIX "decl %0; sete %1"
124	: "+m" (v->counter), "=qm" (c)
125	: : "memory");
126	return c != 0;
127	}
128
129	/**
130	* atomic_inc_and_test - increment and test
131	* @v: pointer of type atomic_t
132	*
133	* Atomically increments @v by 1
134	* and returns true if the result is zero, or false for all
135	* other cases.
136	*/
137	static inline int atomic_inc_and_test(atomic_t *v)
138	{
139	unsigned char c;
140
141	asm volatile(LOCK_PREFIX "incl %0; sete %1"
142	: "+m" (v->counter), "=qm" (c)
143	: : "memory");
144	return c != 0;
145	}
146
147	/**
148	* atomic_add_negative - add and test if negative
149	* @i: integer value to add
150	* @v: pointer of type atomic_t
151	*
152	* Atomically adds @i to @v and returns true
153	* if the result is negative, or false when
154	* result is greater than or equal to zero.
155	*/
156	static inline int atomic_add_negative(int i, atomic_t *v)
157	{
158	unsigned char c;
159
160	asm volatile(LOCK_PREFIX "addl %2,%0; sets %1"
161	: "+m" (v->counter), "=qm" (c)
162	: "ir" (i) : "memory");
163	return c;
164	}
165
166	/**
167	* atomic_add_return - add integer and return
168	* @i: integer value to add
169	* @v: pointer of type atomic_t
170	*
171	* Atomically adds @i to @v and returns @i + @v
172	*/
173	static inline int atomic_add_return(int i, atomic_t *v)
174	{
175	int __i;
176	#ifdef CONFIG_M386
177	unsigned long flags;
178	if (unlikely(boot_cpu_data.x86 <= 3))
179	goto no_xadd;
180	#endif
181	/* Modern 486+ processor */
182	__i = i;
183	asm volatile(LOCK_PREFIX "xaddl %0, %1"
184	: "+r" (i), "+m" (v->counter)
185	: : "memory");
186	return i + __i;
187
188	#ifdef CONFIG_M386
189	no_xadd: /* Legacy 386 processor */
17c0e710	190	raw_local_irq_save(flags);
5abbbbf0 BG	191	__i = atomic_read(v);
5abbbbf0 BG	192	atomic_set(v, i + __i);
17c0e710	193	raw_local_irq_restore(flags);
5abbbbf0 BG	194	return i + __i;
	195	#endif
	196	}
	197
	198	/**
	199	* atomic_sub_return - subtract integer and return
	200	* @v: pointer of type atomic_t
	201	* @i: integer value to subtract
	202	*
	203	* Atomically subtracts @i from @v and returns @v - @i
	204	*/
	205	static inline int atomic_sub_return(int i, atomic_t *v)
	206	{
	207	return atomic_add_return(-i, v);
	208	}
	209
	210	#define atomic_inc_return(v) (atomic_add_return(1, v))
	211	#define atomic_dec_return(v) (atomic_sub_return(1, v))
	212
	213	static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
	214	{
	215	return cmpxchg(&v->counter, old, new);
	216	}
	217
	218	static inline int atomic_xchg(atomic_t *v, int new)
	219	{
	220	return xchg(&v->counter, new);
	221	}
	222
	223	/**
	224	* atomic_add_unless - add unless the number is already a given value
	225	* @v: pointer of type atomic_t
	226	* @a: the amount to add to v...
	227	* @u: ...unless v is equal to u.
	228	*
	229	* Atomically adds @a to @v, so long as @v was not already @u.
	230	* Returns non-zero if @v was not @u, and zero otherwise.
	231	*/
	232	static inline int atomic_add_unless(atomic_t *v, int a, int u)
	233	{
	234	int c, old;
	235	c = atomic_read(v);
	236	for (;;) {
	237	if (unlikely(c == (u)))
	238	break;
	239	old = atomic_cmpxchg((v), c, c + (a));
	240	if (likely(old == c))
	241	break;
	242	c = old;
	243	}
	244	return c != (u);
	245	}
	246
	247	#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
	248
d7f6de1e LB	249	/*
	250	* atomic_dec_if_positive - decrement by 1 if old value positive
	251	* @v: pointer of type atomic_t
	252	*
	253	* The function returns the old value of *v minus 1, even if
	254	* the atomic variable, v, was not decremented.
	255	*/
	256	static inline int atomic_dec_if_positive(atomic_t *v)
	257	{
	258	int c, old, dec;
	259	c = atomic_read(v);
	260	for (;;) {
	261	dec = c - 1;
	262	if (unlikely(dec < 0))
	263	break;
	264	old = atomic_cmpxchg((v), c, dec);
	265	if (likely(old == c))
	266	break;
	267	c = old;
	268	}
	269	return dec;
	270	}
	271
5abbbbf0 BG	272	/**
	273	* atomic_inc_short - increment of a short integer
	274	* @v: pointer to type int
	275	*
	276	* Atomically adds 1 to @v
	277	* Returns the new value of @u
	278	*/
	279	static inline short int atomic_inc_short(short int *v)
	280	{
	281	asm(LOCK_PREFIX "addw $1, %0" : "+m" (*v));
	282	return *v;
	283	}
	284
	285	#ifdef CONFIG_X86_64
	286	/**
	287	* atomic_or_long - OR of two long integers
	288	* @v1: pointer to type unsigned long
	289	* @v2: pointer to type unsigned long
	290	*
	291	* Atomically ORs @v1 and @v2
	292	* Returns the result of the OR
	293	*/
	294	static inline void atomic_or_long(unsigned long *v1, unsigned long v2)
	295	{
	296	asm(LOCK_PREFIX "orq %1, %0" : "+m" (*v1) : "r" (v2));
	297	}
	298	#endif
	299
	300	/* These are x86-specific, used by some header files */
	301	#define atomic_clear_mask(mask, addr) \
	302	asm volatile(LOCK_PREFIX "andl %0,%1" \
	303	: : "r" (~(mask)), "m" (*(addr)) : "memory")
	304
	305	#define atomic_set_mask(mask, addr) \
	306	asm volatile(LOCK_PREFIX "orl %0,%1" \
	307	: : "r" ((unsigned)(mask)), "m" (*(addr)) \
	308	: "memory")
	309
	310	/* Atomic operations are already serializing on x86 */
	311	#define smp_mb__before_atomic_dec() barrier()
	312	#define smp_mb__after_atomic_dec() barrier()
	313	#define smp_mb__before_atomic_inc() barrier()
	314	#define smp_mb__after_atomic_inc() barrier()
	315
96a388de	316	#ifdef CONFIG_X86_32
5abbbbf0	317	# include "atomic64_32.h"
96a388de	318	#else
5abbbbf0	319	# include "atomic64_64.h"
96a388de	320	#endif
5abbbbf0 BG	321
	322	#include <asm-generic/atomic-long.h>
	323	#endif /* _ASM_X86_ATOMIC_H */